Continuous rolled rod direct cooling method and apparatus

ABSTRACT

This disclosure relates to a fluid cooling and lubricating system for metal rod being rolled down from a continuously cast bar and includes a multiple pressure arrangement wherein high pressure fluid is utilized to cool and descale the rod as well as the hot-forming rolls by spraying and wherein low pressure fluid is additionally utilized for cooling and lubrication by flooding roll stand entrance and exit rod-guide housings. Direct and controlled spray cooling of the hot-formed rod is obtained by wide-angled nozzles having solenoid-operated valves responsive to the exit temperature of the rod which is monitored by a photopyrometer whereby the volume of coolant is controlled to obtain a uniform finishing temperature of the rod.

United States Patent [1 1 Coler et al.

[ Oct. 23, 1973 CONTINUOUS ROLLED ROD DIRECT COOLING METHOD AND APPARATUS [75] lnventors: Daniel B. Coier; Francis Marion Mitchell; George C. Ward; Milan Kozak, all of Carrollton, Ga.

7 [73] Assignee: Southwire Company, Carrollton,

[22] Filed: Jan. 13, 1971 [21] Appl. No.: 106,149

[52] U.S. C1 72/13, 72/45, 72/201 [51] Int. Cl B2lb 37/10, B2lb 45/02 [58] Field of Search 72/13, 41, 42, 43,

156,157,115 R, 11.5 A; 266/4 S, 6 S

[56] References Cited UNITED STATES PATENTS 2,067,514 l/l937 Trinks 72/45 2,856,803 10/1958 Fredriksson et a1. 72/201 3,192,752 7/1965 Dowd et al. 72/45 3,212,309. 10/1965 Wilson 72/13 3,465,564 9/1969 Cole et al. 72/201 3,514,984 6/1970 Cook 72/13 2,230,897 2/1941 McBain et al.. 72/201 2,017,403 10/1935 Lorig et a1. 72/45 1,931,912 10/1933 Whitzel 72/201 2,851,042 9/1958 Spence 266/6 S 10/1971 Nara et a1....; 72/8 4/1972 Brown et al. 72/45 OTHER PUBLICATIONS Metals Handbook, 1948 Edition, Page 8597 Primary Examiner-Richard J. Herbst Assistant ExaminerE. M. Combs Att0rney-'Van C. Wilks [57] ABSTRACT noid-operated valves responsive to the exit temperature of the rod which is monitored by a photopyrometer whereby the volume of coolant is controlled to obtain a uniform finishing temperature of the rod.

6 Claims, 5 Drawing Figures FIGI v Q v \NVENTORS DANIEL B. COFER ll FRANCIS M. MITCHELL GEORGE C. WARD w MILAN KOZAK m E Q 6/4426 Lg BY ATTORNEYS PAIENTEflnm 23 1975 3.766763 sum 3 or s v CONTINUOUS ROLLED ROD DIRECT COOLING METHOD AND APPARATUS This invention relates generally to the manufacture of fine wire or like products from metal rod, and particularly to a fluid cooling and lubricating system for metal rod being rolled down from a continuously cast bar.

In copending application Ser. No. 866,410, now US. Pat. No. 3,561,105 and assigned to the assignee of this invention, there is disclosed a method of producing a hot-formed aluminum-base product in which the ascast grain structure of the cast metal is substantially completely destroyed and which is for this reason superior to prior art hot-formed aluminum-base products for drawing into fine wire or other uses.

The method disclosed in the above-identified patent is accomplished by using a continuous casting machine in which molten aluminum-base metal is solidified to obtain a cast metal and a rolling mill to which the cast metal is passed at hot-forming temperature from the casting machine and which has a plurality of roll stands which alternately change the transverse cross-sectional shape of the cast metal. The as-cast grain structure of the cast metal is substantially completely destroyed by deforming the cast metal a substantial number of times to cause an elongation of the cast metal along its axis of elongation by a factor of at least twenty and to cause a substantial movement of the cast metal along a plurality of axes substantially perpendicular to the axis of elongation.

'The present invention is directed to a novel fluid cooling and lubricating system adapted to be used with the rolling mill used to accomplish the method disclosed in the above-identified patent, as well as with other similar apparatus for rolling other metals such as copper or steel rod. In the case of producing aluminum rod as by the method disclosed in the above-identified patent, the method and apparatus disclosed herein result in an aluminum rod that, when 'drawn into aluminum wire by use of standard, prior art drawing techniques, will have higher tensile strength and higher electrical conductivity than the same wire would-have when drawn from rod produced by rolling equipment possessing prior art cooling and lubricating systems.

One problem with rolling mills having prior art cooling and lubricating systems is that once the soluble oilsystem used for cooling and lubrication is set for production, its volume rate of flow is not adjusted though the casting rate, and therefore the velocity of the cast rod through the mill, changes quite frequently during operation. Consequently, the temperature of the rod at the exit from the rolling mill varies during production which results in rod having inconsistent metallurgical properties along its length. For rod being drawn into wire, the uncontrolled temperature variation has an adverse effect on .its tensile strength, elongation and annealability characteristics which is generally solved by our invention.

In the case of copper, for example, (the mill exit temperature of which can varyv between 900 and 1200 F as well as other metals such as steel, the rod may enter a cooling and/or. pickling system upon its exit from the rolling mill. Here again, the variation in the exit temperature of the rolled rod caused by the prior art fixed coolant volume capacity adversely affects the quality of the pickling and the physical properties of the rod. Moreover, tocomply with the highest rod temperature upper limit on the overall production rate of the rod.

The high exit temperature is occasioned by the necessity for rolling the rod at the maximum possible temperature in order to reduce the mechanical power re-.

quirements of the rolling mill. However, in multiple stand mills where the rod is first rolled through a series of roughing stands and then through a series of finishing stands, the power requirements obviously decrease as the rod progresses through the mill. Although the requirement for high temperatures concurrently decreases in each succeeding roll stand, the prior art cooling and lubricating systems have not increased the coolant capacity progressively ineach succeeding stand so as to thereby capitalize on the lower temperature requirements of the mill and hence achieve a lower finishing temperature of the rod.

It is, therefore, the primary object of this invention to provide a fluid cooling'and lubricating system for a rolling mill that produces metal rod having superior and more consistent metallurgical properties.

Another object of this invention is to provide a fluid cooling and lubricating system for a rolling mill wherein variations in the temperature of rod exiting from the mill are substantially eliminated.

Another object of this invention is to provide a fluid cooling and lubricating system for a rolling mill wherein the temperature of rod exiting from the mill is substantially reduced in comparison with exit temperatures resulting from prior art systems.

Still another object of this invention is to provide a fluid cooling and lubricating system for metal rod being rolled down from a continuously-cast bar including a multiple pressure arrangement wherein high pressure fluid is utilized to cool and descale the rod as well as the hot-forming rolls by spraying, and wherein low pressure fluid is additionally utilized for cooling and lubrication and for rod oxidation control by flooding roll stand entrance and exit rod-guide housings. Such flooding also yields a better rod surface by reducing the friction between the rolls and the rod.

A further object of this invention is to achieve a consistent finishing temperature for hot-formed rod exiting from a rolling mill including a fluid cooling and lub-ricating system providing direct and controlled spray cooling of the hot-formed rod through wide-angled spray nozzles having flow control means responsive to the exit temperature of the rod for controlling the volume ofcoolant.

Yet another object of this invention is to provide a fluid cooling and lubricating system for a multiple standrolling mill wherein the volume of coolant is progressively increased in each stand from the inlet to the outlet of the mill whereby rod is rolled in the-primary roughing stands at desirable higher temperatures and finished at the lowest possible temperature consistent with power requirements.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claimed subject matter, and the several views illustrated in the accompanying drawings.

In the Drawings:

FIG. 1 is a semi-schematic elevation view of rodmanufacturing apparatus including a continuous casting machine, multiple stand rolling mill and pickling apparatus upon which the fluid cooling and lubricating system of this invention is adapted to be utilized.

FIG. 2 is a plan view of a single roll stand of the multiple stand rolling mill shown in FIG. 1, and depicts the piping, nozzles and rod-guide housings used in the multiple pressure cooling and lubricating arrangement of this invention.

FIG. 3 is an enlarged generally schematic sectional view taken along line 3-3 of FIG. 2, and depicts the rod supported in a flooded guide housing.

FIG. 4 is an enlarged generally schematic sectional view taken along line 4-4 of FIG. 2, and depicts an idle rollerrod support and seal arrangement for the rod inlet to the guide housing. I

FIG. 5 is a generally schematic fragmentary plan view of two finishing roll stands of the multiple stand rolling mill shown in FIG. 1, and depicts the rod and rolls being sprayed by nozzles having solenoid-operated valves controlled by a photopyrometer which monitors the finishing temperature of the rod.

Referring now to the drawings in detail, there is illustrated in FIG. 1 rod manufacturing apparatus including a continuous casting machine 10, a multiple stand rolling mill 11 and pickling apparatus 12. The continuous casting machine serves as a casting means for solidifying molten metal to provide a cast metal such as a cast bar 13 that is conveyed in substantially that condition in which it solidified from the continuous casting machine 10 to the rolling mill 11. The rolling mill 11 serves as a hot-forming means for hot-forming-the cast bar 13 into a rod 14 of aluminum or another hotformed aluminum-base product in accordance with the method disclosed in the above-identified and commonly assigned U.S. Pat. No. 3,561,105, or a rod of other hot-formed metals such as copper or steel. It should be understood that while the novel fluid cooling and lubricating system of this invention is particularly adapted to be used with the apparatus for accomplish-, ing the method disclosed in the commonly assigned U.S. Pat. No. 3,56l,l05 it is not so limited, and in fact, is useful with hot-forming rolling equipment generally. The continuous casting machine 10 is of conventional casting wheel type similar to that shown in U.S. Pat. No. 3,318,367 and has a casting wheel 15 with a casting groove (not shown) partially closed by an' end less band 16 which is supported against the casting wheel 15 by a plurality of idler wheels 17. The casting wheel 15 and endless band 16 cooperate to provide a mold (not shown) into oneend of which molten metal is poured to solidify and form, and out of the other end of which emits the cast bar 13 in substantially that condition in which it solidified.

The rolling mill 11 includes a plurality of roll stands 18 through 29 which are arranged in alternate horizontal and vertical dispositions to hot-form the cast metal by a series of successive deformations. The continuous casting machine 10 and the rolling mill 11 are posishape of the rod 14. Therod 14 is guided to and from a tioned relative to each other so that the cast bar 13 enters the rolling mill 11 substantially immediately after solidification so as to be in substantially that condition in which it solidified and at a hot-forming temperature within the acceptable range of temperatures for hotforming the cast bar 13. No heating of the cast bar 13 is required between the casting machine 10 and the rolling mill 11, but in the event that it is desired to closely control the hot-forming temperature of the cast bar 13, means for adjusting the temperature of the cast bar (not shown) may be placed between the casting machine 10 and the rolling mill 11.

It will be understood that with the apparatus of FIG. 1, the cast bar 13 may be any one of a plurality of lengths determined only by the amount of molten metal available and will extend in the form of a cast bar between the continuous casting machine 10 and the rolling mill 11. It should be thus apparent that the steps of solidifying molten metal to obtain cast metal and of hot-forming the cast metal, as well as the step of pickling (i.e., copper or steel) the hot-formed cast metal in the pickling apparatus 12, are generally being performed simultaneously once the apparatus of FIG. 1 is in operation.

In the production of rod, the cast metal bar 13 enters the rolling mill 11 through preliminary or roughing stands 18 and 19 and proceeds down its path through a series of finishing stands 20 through 29, out exit point 30 and, if desired, as sometimes is in the case of copper or steel, into the pickling .apparatus 12 downstream from the rolling mill 11. As will become hereinafter apparent, the power requirements for hot-forming, and hence the desired temperature levels, are at a maximum in the roughing stands 18 and 19 and thereafter progressively decrease through the finishing stands 2029.

During the hot-forming of the rod 14 there is employed a water-soluble oil solution for cooling and lubricating purposes. This oil solution is of suitable concentration according to the type rolling mill and the type metal being rolled into rod. In accordance with one aspect of this invention, there is illustrated in FIG. 2 a novel multiple pressure arrangement for'delivering a cooling and lubricating oil solution to one stand of the multiple stand rolling mill 11 of'FIG. 1. The stand includes a frame 31 upon which are suitably mounted hot-forming rolls 32 driven by conventional means (not shown) which will be apparent to those skilled in the art. The rod 14 is adapted to be passed between the rolls 32 which deform the cast metal in the case of roll stand 18, and thereafter change the cross-sectional the rolls 32 by entrance and exit rod-guide housings 33 and 34, respectively. The rod-guide housings 33 and 34 are suitably secu'redto the frame 31 by means of brackets 35 and 36, respectively. I

As seen most clearly in FIG. 3, the guide housing 33 includes an outlet end 37 in which are suitably jour' nalled upper and lower idler roller guides 38 which support the rod 14 through the housing 33. The housing 33 also includes an inlet end 39in which are alsosuitably journalled idler roller guides 40 which provide a similar function as the roller guides 38. As can be seen in FIG. 4, the roller guides 40 may be so arranged as to provide a partial seal around the rod 14 at the inlet end 39 of the guide housing 33. Similar roller guides and seals (not shown) may be provided with the exit rod-guide housing 34. It should be understood, however, that the specific structure shown in FIGS. 3 and 4 is for illustrative purposes only and is not intended to limit the general concept of the invention. In fact, any method of rod guiding, supporting, and sealing may be utilized within the scope of the appended claims.

Low pressure fluid coolant C, such as soluble oil, is directed through piping 41 from a source (not shown) into the rod-guide housing 33 at a point near the rod inlet end 39. The rod-guide housing 33 fills or floods in the same manner as a sink with a drain too small to remove the fluid as fast as it enters. The fluid coolant C therefore surrounds the rod 14 as shown in FIG. 3 to cool both housing 33 and the rod 14. Exiting fluid may be directed out of the rod outlet end 37 of the housing 33 towards the rolls 32 to reduce the friction between the rod and the rolls and also to lubricate and cool the rolls. The partial seal arrangement effected by the idler guide rollers 40 at the inlet end 39 of the housing 33 assures that the major portion of the overflowing coolant C will be directed out of the outlet end 37 towards the forming rolls 32. Both the guide housing 33 and the forming rolls 32 are protected by, the cooling and lubricating action of the fluid coolant C. The reduced friction between the rod and the rolls, meaning less friction than in prior art rolling mills, yields a rod having better rod surface quality than prior art rod.

Low pressure fluid coolant is also directed through piping 42 to the rod-guide exit housing 34 and delivered near the point where the rod 14 exits therefrom. It should be apparent, therefore, that the coolant C will be directed through the housing 34 in counterflow relationship to the movement of the rod 14 therethrough. The coolant C floods the exit housing 34 and then spills out to flood the rolls 32 in a manner similar to the flooding of the entrance housing 33.

The rod stand illustrated in FIG. 2 also includes spray blocks 43 suitably secured to the frame 31. Each of the spray blocks 43 has two adjustable spray nozzles 44 and 45. Fluid coolant from a source (not shown) .is conducted through piping 46 to the spray blocks 43 where it is emitted by the spray nozzles 44 and 45. Low pressure sprays (albeit of higher pressure than found in pipes 41, 42 and in guides 33, 34) emitted by the spray nozzles 44 are directed against the rolls 32 for the purpose of cooling and lubricating the rolls 32 as well as for removing surface scale, picked up by the rolls from the rod 14 during working, which scale tends to be deposited upon and to build up uponthe surface of the rolls 32. This deposit is detrimental to the surface quality of the subsequent rod produced as well as being detrimental to the'u'seful service of the rolls 32. I

High pressure sprays emitted from the nozzles are directed against the junction of the rolls 32 and the rod 14 for the purpose of removing surface scalefrom the rod 14 as well as in assisting in thec ooling of the rod 14. The nozzles 44 and 45 may be made adjustableas to angle of spray and flow rate in accordance with known, prior art nozzle technology, so as to provide flexibility in both spray pattern and volume for both the roll 44 and rod 45 sprays.

Additionally, further spray blocks similar to blocks 43 may be mounted on frame 31 in the vicinity of points 88. These additional spray blocks would possess spray nozzles similar to rod spray nozzle 45 and roll spray nozzle 44 for spraying fluid on rod 14 and rolls 32 respectively. Thus, these additional spray blocks would augment the beneficial rod surface and friction effects provided by the exiting fluid directed out of rod outlet end 37, and it should be noted that in addition to reduced friction and better rod surface quality, the combined effect of all of these fluid flows is to provide a measure of rod oxidation control within the rolling mill by preventing exposure of the rod surface to the atmosphere within the mill. This is especially so within the flooded interiors of guides 33, 34 where virtually no contact between the atmosphere and the'rod is possible. I

One beneficial effect of our thus described invention has been found in the production of the ordinary, industry-wide, standard aluminum EC rod. It has been found that when aluminum EC rod produced in accordance with our invention is subsequently drawn into wire by use of standard, prior art drawing techniques, the wire will have both higher tensile strength and higher electrical conductivity than the same wire would have when drawn from rod produced by rolling equipment possessing prior art cooling and lubricating systems. For instance, the normal increase in tensile strength which occurs when prior art EC rod is drawn into wire is between 7,000 and 12,000 lbs./in. But using our invention, the wire generally experiences an increase in tensile strength of between 8,500 and 18,000 lbs./in. yet it still remains flexible enough not to be classified as brittle. Also, wire drawn from rod which has been produced in accordance with our invention has a higher average tensile strength than vdoes prior art wire. Our wire also exhibits a greater range of tensile strengths in computing one and two standard deviations from the average tensile strength than does prior art wire. As for the conductivity, the average conductivity in priorart wire drawn from EC rod containing 0.24% Fe is 61.0 percent IACS (International Annealed Copper Standard), but using our invention, the average conductivity of the wire has been found tobe 61.9 percent IACS. This is significant when you compare it to pure aluminum which is only :64.0 percent IACS.

It should be thus apparent that the multiple pressure cooling and lubricating system illustrated in FIGS. 2-4 provides low pressure fluid for cooling the rod 14 and lubricating the rolls 32 by the flooding of and subsequent spill-over from the guide housings 33, 34 while simultaneously providing multiple, relatively high pressure flu d sprays for spraying the rolls 32 and rod 14 to achieve descaling and additional cooling, all of said sprays helping to reduce rod oxidation. While the above-described multiple pressure system is specifically disclosed herein as being 'applied to only one of the roll stands of the multiple stand mill 11 illustrated in FIG. 1, it should be readily apparent that the system in actual practice may be applied to any number or all of the stands in accordance with the particular cooling and lubricating requirements dictated by the metal being formed and the specific design of the rolling equipment. v

Referring now to FIG. 5, there is illustrated apparatus for direct and controlled cooling of the rod 14 which facilitates the production of rod with the lowest possible finishing temperature, while at the same time substantially eliminating variation in the finishing temperature so as to obtain rod with consistent metallurgical properties along its length. Although FIG. 5 illustrates the direct and controlled cooling apparatus applied only to the last two finishing roll stands 28 and 29, it is to be understood that the system could apply to all the roll stands or only to all the finishing roll stands 20-29 inclusive. The primary roughing stands, in the latter case, could be provided with the multiple pressure cooling and lubricating system shown in FIG. 2, for instance.

As discussed above, the rod 14 is rolled in the mill 11 at the maximum possible temperatures in order to reduce the mechanical power requirements of the mill. On the other hand, in the case of copper or steel rod which is treated in the pickling apparatus 12 subsequent to hot-forming in the mill 11, it is especially desirable to finish the rolling operation at the lowest possible temperature so that not only is rod oxidation reduced by the pickling apparatus 12 may be designed for a lower capacity than would be needed to accommodate higher temperature rod while simultaneously being more efficient and capable of operating at essentially higher production rates. In accordance with this invention, these divergent temperature criteria are accommodated by rolling the rod 14 in the primary roughing stands 18 and 19 at the maximum possible temperatures and thereafter, as the power requirements progressively decrease, rolling the rod 14 at progressively lower temperatures through the finishing stands 20-29 so that the rod 14 exits from the mill 11 at the lowest desired temperature which from a metallurgical point of view for copper, for example, may be between 700 and 800 F. This is accomplished by progressively increasing the volume of cooling fluid applied directly to the rod 14 at each roll stand as the rod 14 moves through the mill 11. The volume of cooling fluid is at a minimum at stand 18 and increases progressively to a maximum at stand 29.

The direct and controlled cooling of the rod 14 may be achieved by providing each of the finishing roll stands 20-29 with primary and secondary nozzle blocks 48 and 47, respectively. The secondary nozzle blocks 47 include wide-angled spray nozzles 49 which direct a wide-angled spray of coolant fluid against the hotforming rolls 32. The primary nozzle blocks 48 also include wide-angled spray nozzles 50 which direct a wide-angled spray of coolant fluid against the hotforming rolls 32. In addition, however, the primary nozzle blocks 48 also include wide-angled spray nozzles 51 which direct a high pressure wide-angled spray of coolant fluid directly on the rod 14. The pressure of the fluid coolant conducted to the nozzle blocks 48 through piping 52 may be monitored by pressure sensing means such as pressure gauges 53. Flow control means such as valves 54 in'the piping 52 may be adjusted to control the volume of coolant delivered to each of the nozzle blocks 48. Nozzles 49,50,51 are adjustable as to the width of the spray angles.

It should be apparent, therefore, that the wide-angled sprays emitted from the nozzles 49, 50 and 51, as well as the direct cooling of the rod 14 by the spray from the nozzles 51, coupled with direct control of the coolant pressure at each roll stand, results in more effective cooling which lends itself to a greater degree of control and thus permits the selective temperature variation through the mill 11 as discussed above.

In order to achieve a uniform finishing temperature for the rod 14, the apparatus illustrated in FIG. includes a temperature sensing means such as photopyrometer 55 which permits a constant monitoring of the temperature of the rod 14 as it exits from the mill 11. Temperature sensing means 55 is electrically connected, as shown schematically by the dotted lines 56 in FIG. 5, to a valve actuating means such as electromagnetic solenoid actuators 57 which, when commanded to do so by controllers 90, operate the flow control means 54 and thus control the flow of coolant into the nozzle blocks 48. As the photopyrometer 55 monitors the temperature of the hot-formed rod 14 and this is relayed through thecontrollers 90 to the electromagnetic solenoid actuators 57, the flow of coolant is adjusted during the rolling operation and according to the need and as required by the temperature of the rod 14 to maintain the rod temperature at a constant level. Coolant piping to each of the roll stands 18 through 29 is throttled by separate valves with separate electromagnetic solenoid actuators 57, each actuator 57 being connected through separate controllers 90 with the photopyrometer 55. The temperature of the rod 14 at the exit from the mill 11 thus controls the coolant flow in each individual stand through this arrangement. The coolant flow, therefore, is no longer fixed, as in the prior art, but is now variable and thus both more efficient and more effective. In the case of copper rod, for instance, this controlled, more effective cooling produces copper rod having a lower, more consistent annealing temperature-a highly desirable result. One theory explaining this phenomenon is that the impurities which are in solution within the copper are given a uniform, relatively long cooling period during which they precipitate into the copper grain boundaries where they are much less detrimental to annealing than prior art impurities which are trapped in solution by a relatively quick quenching process such as being immediately plunged from a temperature as high as l,l00 F into a cooling and/or pickling system. Rod produced in accordance with our invention also has higher tensile strength and lower elongation characteristics than prior art rod.

In view of the foregoing, it should be readily apparent that there is provided in accordance with this invention a novel fluid cooling and lubricating system for a rolling mill that permits the rolling down of rod from cast metal at maximum possible temperatures while'achieving the lowest possible finishing temperature, and simultaneously controlling the cooling to obtain a uniform finishing temperature thereby improving the effects of a pickling operation, if required, as well as resulting in wire drawn from the rod having higher tensile strength and lower elongation characteristics.

Although only preferred embodiments of the invention have been specifically illustrated and described herein, it is to be understood that minor variations may be made without departing from the spirit of the invention.

We claim:

1. In a rolling mill for rolling a cast metal bar selected from the group of copper, aluminum, and steel into an elongated metal rod, said rolling mill possessing individual roll stands located between an entrance and an exit to said mill, the improvement comprising gradual cooling means for progressively increasing the degree of cooling between the entrance to the mill and the exit to the mill, said gradual cooling means comprisingadditional means for progressively increasing the volume of flow of a cooling and lubricating fluid between the entrance and the exit to the mill, said additional means being responsive to temperature sensing means.

2. The improvement of claim 1 in which the temperature sensing means comprises a photopyrometer.

3. The invention of claim 1 in which said fluid pressure volume varying means comprises a photopyrometer to sense the temperature of the rod, electromagnetic solenoid valves associated with each roll stand for controlling the flow of fluid to that particular roll stand, and means connecting said photopyrometer to said solenoid valves.

4. In a rolling mill for rolling a cast metal bar selected from the group of copper, aluminum, and steel into an elongated metal rod, said rolling mill possessing a plurality of individual roll stands having entrances and exits and a fluid cooling and lubricating system, the improvement comprising means for increasing and decreasing the pressure and volume of flow of fluid in response to a corresponding increase or decrease in the temperature of the rod as measured at the exit of the last stand by a temperature sensing means, said means for increasing and decreasing the pressure and volume of flow of fluid being constructed in such a manner that the volume of flow of fluid for any one temperature is least at the entrance to the rolling mill and gets progressively greater towards the exit to the rolling mill.

5. The improvement of claim 1 and further including wide angle spray nozzles for directing a flow of fluid directly onto the rod after the rod has passed through each roll stand. I

6. A method of producing copper rod which, when drawn into wire using prior art drawing techniques, will have a lower annealing temperature comprising the steps of:

rolling continuously cast copper bar down into copper rod in successive steps,

measuring increases and decreases in copper rod temperature after the last of said successive steps, applying a cooling and lubricating fluid to the copper rod during rolling,

providing a volume of flow of said fluid for any given rod temperature which volume is least during the beginning of the successive rolling steps and which volume of flow progressively increases towards the last of said successive rolling steps, and 3 increasing and decreasing the pressure and volume of flow of said fluid in response to a correspondingly measured increase or decrease in rod temperature. 

1. In a rolling mill for rolling a cast metal bar selected from the group of copper, aluminum, and steel into an elongated metal rod, said rolling mill possessing individual roll stands located between an entrance and an exit to said mill, the improvement comprising gradual cooling means for progressively increasing the degree of cooling between the entrance to the mill and the exit to the mill, said gradual cooling means comprising additional means for progressively increasing the volume of flow of a cooling and lubricating fluid between the entrance and the exit to the mill, said additional means being responsive to temperature sensing means.
 2. The improvement of claim 1 in which the temperature sensing means comprises a photopyrometer.
 3. The invention of claim 1 in which said fluid pressure volume varying means comprises a photopyrometer to sense the temperature of the rod, electromagnetic solenoid valves associated with each roll stand for controlling the flow of fluid to that particular roll stand, and means connecting said photopyrometer to said solenoid valves.
 4. In a rolling mill for rolling a cast metal bar selected from the group of copper, aluminum, and steel into an elongated metal rod, said rolling mill possessing a plurality of individual roll stands having entrances and exits and a fluid cooling and lubricating system, the improvement comprising means for increasing and decreasing the pressure and volume of flow of fluid in response to a corresponding increase or decrease in the temperature of the rod as measured at the exit of the last stand by a temperature sensing means, said means for increasing and decreasing the pressure and volume of flow of fluid being constructed in such a manner that the volume of flow of fluid for any one temperature is least at the entrance to the rolling mill and gets progressively greater towards the exit to the rolling mill.
 5. The improvement of claim 1 and further including wide angle spray nozzles for directing a flow of fluid directly onto the rod after the rod has passed through each roll stand.
 6. A method of producing copper rod which, when drawn into wire using prior art drawing techniques, will have a lower annealing temperature comprising the steps of: rolling continuously cast copper bar down into copper rod in successive steps, measuring increases and decreases in copper rod temperature after the last of said successive steps, applying a cooling and lubricating fluid to the copper rod during rolling, providing a volume of flow of said fluid for any given rod temperature which volume is least during the beginning of the sucCessive rolling steps and which volume of flow progressively increases towards the last of said successive rolling steps, and increasing and decreasing the pressure and volume of flow of said fluid in response to a correspondingly measured increase or decrease in rod temperature. 